The invention relates to a telephone set with a base station and a control panel detachable therefrom, the base station and the control panel comprising each a means for communicating with each other in a cordless manner.
Such a telephone set is known from EP-A-0396190. That publication describes a telephone set whose keypad for dialling telephone numbers can be detachably connected to both the base station and the operation panel. With prior-art telephone set it is possible to hold a conversation with both the base station and the operation panel, the keypad being optionally connectable to either.
Japanese Patent Application no. 62-110252 further discloses a telephone set with a detachable keypad, in which the keypad comprises an infrared send portion and the telephone set an infrared receive portion, so that it is possible for a person to dial a number while being remote from the telephone set.
Recently, telephone sets have been proposed comprising a display panel, for example, an LCD screen, with texts being displayed on the screen that relate to both a telephone call itself and to a list of names with the associated preselect keys, the number of the calling party, the called telephone number and so on, as well as information about service companies such as viewdata, mail order businesses, banks, travelling agencies and so on. Prior-art telephone set also includes an extensible alphanumeric keypad by which text can be input and displayed on the display panel. In this manner a simple communication with one of said service companies is possible. This prior-art telephone set is marketed by the Applicants under the name of Philips Enhanced Telephone.
Finally, EP-A-0421025 to which U.S. Pat. No. 5,231,381 has disclosed a data processing system consisting of a flat display panel which comprises a so-called touch-screen for inputting data with a finger and a graphic tablet for inputting data with a special pen. With this system it is possible to use a flat, compact unit both for inputting texts and/or figures into a computer with a special pen and inputting texts and data with a finger by touching a virtual keypad. Furthermore, the system can also display texts and figures. As a result, prior-art system is pre-eminently suitable for use as an interactive interface between a user and a (portable) personal computer.